Wikipedia - The elephant in the room (or in the living room)

 

The expression “the elephant in the room” (or "the elephant in the living room")[2][3] is a metaphorical idiom in English for an important or enormous topic, question, or controversial issue that is obvious or that everyone knows about but no one mentions or wants to discuss because it makes at least some of them uncomfortable and is personally, socially, or politically embarrassing, controversial, inflammatory, or dangerous. 

The metaphorical elephant represents an obvious problem or difficult situation that people do not want to talk about. [1][4][5]
It is based on the idea/thought that something as conspicuous as an elephant can appear to be overlooked in codified social interactions and that the sociology/psychology of repression also operates on the macro scale. 

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The term refers to a question, problem, solution, or controversial issue which is obvious to everyone who knows about the situation, but which is deliberately ignored because to do otherwise would cause great embarrassment, sadness, or arguments, or is simply taboo. The idiom can imply a value judgment that the issue ought to be discussed openly, or it can simply be an acknowledgment that the issue is there and not going to go away by itself.
The term is often used to describe an issue that involves a social taboo or which generates disagreement, such as race, religion, politics, homosexuality, mental illness, or suicide. It is applicable when a subject is emotionally charged; and the people who might have spoken up decide that it is probably best avoided.[13]

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The idiom is commonly used in addiction recovery terminology to describe the reluctance of friends and family of an addicted person to discuss the person's problem, thus aiding the person's denial. Especially in reference to alcohol abuse, the idiom is sometimes coupled with that of the pink elephant, "the pink elephant in the room."[citation needed]
The expression has also been used as a metaphorical idiom in Spanish. In 1994, the 8000 Process was a legal investigation of a Colombian presidential campaign. There were accusations that the campaign of Colombian Liberal Party candidate Ernesto Samper was partially funded with drug money from the Cali Cartel. Insisting on his innocence, Samper stated that if drug money had entered the presidential campaign, it had done so "behind his back". 

Cardinal Pedro Rubiano, a leader of Colombia's Catholic Church, stated in an interview that not knowing that drug money financed part of the presidential campaign was similar to not noticing "an elephant entering one's living room".[14][15] Since then, the events that led to drug money financing the "Samper for President" campaign have been referred to as "The Elephant."
The title of Alan Clarke's 1989 television film Elephant references the term. This was in turn influential in the naming of Gus Van Sant's 2003 film of the same name, although Van Sant thought a different expression was being referenced.
Alexandra Burke's 2012 single "Elephant" also uses the concept,[16] as does a poem by Terry Kettering, entitled The Elephant in the Room.[17] In a November 2013 edition of Time magazine, New Jersey governor Chris Christie was labeled as the "Elephant in the Room" on the cover page.[18]  

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